The literature is replete with descriptions of trocar devices, particularly surgical trocar devices. For example, a conventional trocar may include, for example, a seal, a sharp trocar, a cannula, and a safety shield to protect organs once the trocar has penetrated the abdominal wall. The safety shield is generally designed as a mechanical device which is spring-loaded and activated when the trocar tip is inserted into the cannula. The tip of the trocar is protected by the safety shield. As the trocar passes through the layers of the abdominal wall, the safety shield is retracted, exposing the sharp tip of the trocar. When the device finally penetrates the Het layer of abdominal tissue, and just prior to entering the open space of the abdomen, the safety shield moves forward to again cover the trocar tip.
The instrument described above suffers numerous disadvantages. For example, if the mechanical safety shield were to become stuck, due to abdominal wall tissue becoming entrapped, the safety shield would not spring forward to cover the sharp trocar. In this case, damage could occur. In fact, damage does occur in a certain number of surgical cases annually. In addition, an unpredictable force is generally required to overcome the resistance of the tissue of the abdominal wall. This force is provided by the user pushing linearly, the trocar handle toward the abdomen. Since the force is variable and unique to the given tissue composition, the user cannot accurately predict how much force may be required on any given insertion.
A further disadvantage of the above-described instruments and systems is the lack of any feedback to the operator as to when then instrument has actually entered into the abdominal cavity. This can lead to damage of vital organs and misuse of the instrument.
A further disadvantage of the above-described instruments and systems is that such instruments and systems typically require manual manipulation and operation. This then requires the user to interpret what constitutes excessive force. When excessive force is used, damage to vital organs can occur.
A further disadvantage of the above-described instruments and systems is that such instruments and systems typically utilize a diamond-pointed-like trocar which penetrates the abdomen like a nail penetrates wood when hammered. This trocar placement method does not account for the potential variation in tissue thickness, tissue variability within the abdominal wall, and does not allow for counter-traction which would provide the users with the need to apply less force.